/Engine/Plugins/Importers/USDImporter/Source/USDStage/Public/USDStageActor.h
Loads the assets for all prims from StartPrim and its children
bool LoadAssets ( [FUsdSchemaTranslationContext](API\Plugins\USDSchemas\FUsdSchemaTranslationContext) & TranslationContext, const [UE::FUsdPrim](API\Plugins\UnrealUSDWrapper\UsdWrappers\FUsdPrim) & StartPrim )